Low-temperature synthesis of lead-free Cs₂AgBiBr₆ double-perovskite ink

Reduced toxicity and better atmospheric stability have made the Cs₂AgBiBr₆ double-perovskite material a promising photo-absorbing material to replace lead halide-based perovskites in solar photovoltaic applications. In this work, for the first time, a novel low-temperature method for the synthesis of lead-free Cs₂AgBiBr₆ double-perovskite ink, using a salt solution of the constituents of Cs₂AgBiBr₆ at a temperature of as low as 50°C, is reported. An X-ray diffraction study confirmed the presence of the Cs₂AgBiBr₆ double-perovskite crystal structure, and an ultraviolet–visible absorption study was done to calculate the band gap. Particle size analysis showed that the particle size of the prepared ink lies in the range 700–1000 nm, and scanning electron microscopy was done on a spin-coated substrate to examine the microstructural features of the ink. The present work will help develop further a low-cost and simple method for the development of double-perovskite ink.